Construction of electronic equipment



D. L. SWALE CONSTRUCTION OF ELECTRONIC EQUIPMENT Filed Aug. 25, 1955 3 Sheets- -Sheet 1 g I! i Qg D c, 1, 1959 D. L. SWALE 2,915,679

CONSTRUCTION OF ELECTRONIC EQUIPMENT Filed Aug. 25, 1955 3 Sheets-Sheet 2 g in 13 1 I e a I :i i I @L E i I Eg j? 13 #1 I I (92 17 u, za m H L l 31514...

ZZL/IEILZHE Dec. 1, 1959 D. L. SWALE CONSTRUCTION OF ELECTRONIC EQUIPMENT 3 Sheets-Sheet 3 Filed Aug. 25, 1955 ru f Ina-mu 2 L. 5 W41. E

PIT/I with the interior of the channel. .tion the cooling air may be forced over the valves whilst -avoidingiany air stream on-the resistors and other com- CONSTRUCTION OF ELECTRONIC EQUIPMENT David Lionel Swale, London, England, assignor to The Decca Record Company Limited, London, England, a British company Application August 25, 1955, Serial No. 530,592

- Claims priority, application Great Britain August 25, 1954 7 Claims. (Cl. 317-101 This invention relates to the construction of electronic equipment.

It is well known to construct complex electronic equipment ,in the form of a number of units which can be separately removed and replaced. A unit construction provides considerable advantages, notably in ease of thus it becomes a simple matter to provide various types of displays according to requirements making use of standard units.

The present invention is directed more particularly to the construction of such units and, according to the invention, a unit for use in electronic equipment comprises a U-shaped channel with outwardly-directed flanges on the side Walls of the U, valve holders being mounted on the base of the U between the side walls thereof. Preferably all or at least a majority of the resistors, condensers and like components are mounted between the flanges and the outer faces of the side walls of the U. This construction permits of easy access to the components thereby facilitating servicing of the equipment.

The side walls are preferably formed as continuous walls of uniform height, the height being sufficient that none of the valves protrude above the top of the walls.

Preferably the flanges are at the outer edges of the sidewalls of the U and the resistors and other compo-' nents arranged between the flange and the side walls of the-U at an angle to the plane of the latter. Positioning the components in this manner is a further feature facilitating ease of servicing.

The form of unit described above, when installed in a mounting can be arranged to provide an air duct for f'cooling the valves, since the latter are situated in the channel of the U. Conveniently the units are assembled in the mounting with the U-shaped channels inverted. By providing a solid base for supporting the unit, the channel of the U is formed into a closed duct and the units are preferably positioned so that air can be forced through the'channels from one end thereof for cooling the valves. For example, the units may be positioned with one end of the channel adjacent a face plate on the mountinghaving an aperture which communicates By such a construc- United States Patent "ice ponents on the outer side of each unit. This is often advantageous in avoiding or reducing instability due to variations in component values.

Each unit may be made so that it can be lowered directly onto its mounting and then secured in position by one or more bolts and, in this construction, a plug and socket assembly may be provided for making electrical connections to the unit, one part of the plug and socket assembly being fixed to the unit and the other part to the mounting in such manner that the plug engages the socket on downward movement of the unit onto the base plate of the mounting. In an alternative construction, the unit can be lowered into its mounting and then moved in the axial direction of the channel so as to bring into engagement, by the axial movement, a plug and socket for electrically connecting the unit to wiring in the mounting. Screw means may be provided for effecting an axial movement of the unit. Such screw means may be suflicient to secure the unit in position but if desired a clamp or clamps may be provided. The screw means may comprise a screw with a knurled knob at one end, the screw engaging a fixed threaded bush on the mounting. The end of the screw remote from the knob may be provided with a cylindrical head having a circumferential channel in the cylindrical surface, which channel engages a fork or the like on the unit, the fork straddling the screw. The axial movement of the unit may conveniently be arranged not only to engage the plug and socket but also to bring the channel into engagement with the air supply duct by forcing one end of the unit tightly against a plate on the mounting having an aperture as described above.

The plug and socket are preferably provided with a locating peg to ensure that the pins are correctly engaged. Preferably also the unit and mounting have mutually engaging male and female elements to ensure correct 10- cating during the axial movement.

Although the unit described above is particularly suit able for forced draught ventilation as described above, it may also be used in an assembly in which the channel is stood on end to provide convection current cooling, the unit being fitted in a suitably louvred container to permit adequate air flow.

if the unit as described above, having flanges at the outer edges of the side Walls, is arranged for use with the channel inverted, it is convenient to provide two or more handles bridging over the top of the unit, i.e. over the base of U (considering the channel in the inverted position), not only to facilitate lifting the unit out of an assembly but also to enable the unit to be stood upsidedown on the handles to permit of ready access to the valves in the channel.

The form of unit described above may conveniently be made out of a light .alloy casting. It may be formed as a single integral casting or it may be formed in a number of sections, for example two end sections joined by a central section. Making the unit in sections facilitates the construction of units having a number of different types of valve holders since sections suitably formed may be readily joined together.

As indicated above unit costruction is particularly applicable to radar display systems and it has been found particularly advantageous to use of a number of small units in such a radar display. It will be appreciated that many of the more complex radar systems require very accurate control of voltages and the like and it is a common practice in such systems to utilize complex circuits employing servo loops for maintaining the required stability. It has been found particularly convenient to construct each servo loop as a separate unit may thus be readily replaced if there should be any fault in the unit.

Each unit is preferably provided with a number of readily accessible test points, e.g. for the input and output signals, to which test instruments can be connected.

The following is a description of two embodiments of the invention, reference being made to the accompanying drawings in which:

Figure 1 is a side elevation of a unit for use in electronic equipment,

Figure 2 is an end view of the unit of Figure 1,

Figure 3 is an underside plan view of the unit of Figure 1,

Figure 4 is a section along the line 44 of Figure 3,

Figure 5 is a side elevation of another construction of the unit shown in its mounting, part of the unit being cut away to show internal details, and

Figure 6 is a plan view of the unit of Figure 5.

Referring to Figures 1 to 4, there is shown a unit in the form of an inverted U-shaped channel, in the form of a plate It) with the two downwardly-extending side walls 11 which, at their lower ends, are provided with outwardly-extending flanges 12. This unit is formed of sheet metal and is strengthened by flanges 13 on each end of the unit, these flanges 13 enabling the channel unit to be bolted to a pair of end plates 14 which are provided with two apertures 15, 16. The unit is carried on a base in the form of a tray 17 (shown in chaindotted lines in Figure 4) having a pair of threaded bushes 18 which may be engaged by a pair of screw rods 19 securing the unit in position on the base. Mounted on the base tray 17 are a pair of multi-hole sockets for engaging two plugs 2% on the underside of the unit. The screw rods 19 are provided with conical ends for assisting in the locating of the unit correctly on the base 17 to permit of the plug pins entering their respective socket holes before the rods 19 are screwed down.

All the valves 25 to be carried on the unit are mounted on the underside of the plate It Resistors and condensers are, as far as possible, mounted on the outer side of the unit between the side walls 11 and the flanges 12. Some of these components, as indicated at 26, are arranged between soldering tags 27 stretching along the upper side of the walls 11 and soldering tags 28 arranged at the outer ends of the lower flanges 12. Smaller components may he arranged, as indicated at 29, between the upper soldering tags 27 and central soldering tags 30 carried on pillars 31 secured along the centre line of the side walls 11 and, as indicated at 32, between these central tags 30 and lower tags 23.

An eight-way test socket 33 is mounted on pillars 34 so as to be readily accessible at the top of the unit. To each of the socket pins are applied signals from various points in the circuit of the unit to enable the signals to be applied to test instruments. The particular signals would be chosen as those having characteristics useful in maintenance 'work. In complex electronic apparatus, closed circuit loop are commonly employed for maintaining accurate control of voltages and the like. Each unit may be arranged to carry one or more such loops and, in this case, it is generally desirable that the test socket enables the input and output of the loop or of each loop to be tested.

The unit thus far described may be positioned with the apertures 16 in the two end plates adjacent respectively an inlet and an outlet for an air stream which is thus constrained to flow over the valves 25. It will be noted that the aperture 16 is of such size that this air stream will blow only through the duct formed by the inverted U-shaped unit and the tray 17 but will not blow over the condensers and resistors mounted on the outer side of the unit.

Figures 5 and 6 illustrate a modified form of the construction of Figures 1 to 4 and for convenience in illustrating this modified form, the valves and resistors have been omitted. In Figures 5 and 6 the unit is an inverted U-shaped channel formed by a flat plate 4t having downwardly-extending side walls 41 terminated in outwardly-extending flanges 42. In this particular construction, the plug 43 for effecting connections to the external wire is mounted on one end of the unit for engagement with a socket 44 secured on an upstanding end plate 45 of a mounting tray 46. To bring the plug into engagement with the socket, the unit has to be lowered onto the mounting tray 46 and then moved in the axial direction of the channel. To facilitate lifting, the unit is provided with carrying handles 47 each comprising a rod bent in the form of an inverted U. At the end remote from the plug 43, the unit has an end plate 48 with a slot extending upwardly from its lower edge. This slot fits closely over a reduced diameter portion 49 of a screw 50 having a handle 51 suitably formed for manual rotation. This screw engages a threaded bush 52 on the mounting 46 and thus serves for moving the unit axially in the mounting so as to bring the plug from the position shown in Figure 5 (i.e. not in engagement with the socket) to the position shown in Figure 6 in which the plug engages the socket. To ensure proper alignment of the plug pins, locating pegs 53 are provided on the end wall 45 which engage in corresponding holes on the unit just before the plug pins enter their socket.

In the arrangement of Figures 5 and 6, the plates 45 and 48 are provided with apertures similar to the apertures 15, 16 of Figures 2 and 4 so enabling, when the unit is disposed between an inlet and an outlet for an air-stream, the valves which are mounted on the underside of the plate 4-9 to be cooled without air being blown over the resistors and condensers which, as far as possible, are mounted on the outside of the unit between the side walls 41 and the flanges 42 in a similar manner to that illustrated in Figures 1 and 4.

Instead of providing a forced air-stream as described above, in some cases the units may be mounted with the channels vertical for cooling the valves by convection.

It will be seen that, in each of the two arrangements illustrated in the drawings, the unit is readily removable from its mounting and that, when so removed, easy access is obtained to all the components for servicing. F urthermore, the valves may readily be cooled without having any air-stream over the components on the outer sides of the units.

I claim:

1. In electronic equipment, a unit comprising a U- shaped channel with an outwardly-directed flange on at least one of the side walls of the U and with valve holders mounted on the base of the U between the side walls thereof, in combination with a mounting for said unit, said mounting having a base plate and said unit being arranged with the U-shaped channel inverted on the base plate so that the base plate together with the side walls and base of the U form a closed duct through the unit.

2. The combination as claimed in claim 1 wherein the mounting has an apertured face plate extending upwardly from said base plate and wherein said unit is positioned with one end of the channel adjacent the face plate so that the aperture communicates with the interior of the channel.

3. The combination as claimed in claim 1 wherein a plug and socket assembly is provided for making electrical connections to the unit, one part of the plug and socket assembly being fixed on the unit and the other part on the mounting in such manner that the plug engages the socket on downward movement of the unit on to the base plate of the mounting.

4. The combination as claimed in claim 3 wherein at least one bolt is provided for holding said unit in said mounting.

5. The combination as claimed in claim 1 wherein a plug and socket assembly is provided for making electrical connections to said unit one part of the plug and socket assembly being on said unit and the other on said mounting for engaging by movement in the axial di- 5, rection of the channel, and wherein said mounting is made longer than said unit so that said unit can be lowered into the mounting and then moved in the axial direction of the channel to bring the plug and socket into engagement.

6. The combination as claimed in claim 5 wherein screw means are provided for efiecting axial movement of said unit.

7. In electronic equipment, the combination of a unit and a mounting, said unit comprising a U-shaped channel with continuous side walls of uniform height in planes at right-angles to the plane of the base of the U and with an outwardly-directed flange on at least one of the outer edges of the side walls of the U, valve holders being mounted on the base of the U between the side walls thereof and resistors, condensers and like components being mounted between the flanges and the outer faces of the side walls of the U, and said mounting having a base plate and said unit being arranged with the U-shaped channel inverted on the base plate so that the base plate together with the side walls and base of the U form a closed duct through the unit.

References Cited in the file of this patent UNITED STATES PATENTS 2,602,842 Morris July 8, 1952 2,658,101 Coxe Nov. 3, 1953 2,046,927 Riley July 7, 1956 FOREIGN PATENTS 563,197 Great Britain Aug. 2, 1944 712,826 Great Britain Aug. 4, 1954 

